The BioSAFTM consists of a containment vessel made in either GRP, GCS, coated mild steel, stainless steel or concrete with internal dividing walls, internal air and water distribution systems, charge of plastic media and internal support structure.

The media provides a large surface area on which the bacteria attach themselves to grow and live.

Wastewater is introduced into the base of the BioSAFTM unit into the under decking plenum space. Air is introduced into the BioSAFTM through a separate diffuser system also located near the base of the unit. An air blower supplies oxygen to the BioSAFTM environment on a continuous basis. The air and water distribution system design is such that it creates a very effective mixing pattern within the BioSAF. This pattern allows for rapid distribution of the wastewater throughout the packed media bed, which produces a homogeneous solution in full contact with the entire microbial population for the period of time that the wastewater is in the reactor.

The uniform mixing pattern is of key importance in providing a stable environment which has the ability to smooth out fluctuations that may occur in the influent concentrations. The high media voidage eliminates the need for backwashing, thus reducing the costs and ensures minimal disruption of the biological process.

Because of the high media porosity, BioSAFTM is characterised by high retention times, making them ideally suited to both BOD5 removal and nitrification of wastewater. The neutral buoyancy of the media also simplifies reactor construction and maximises active biological volume.

• Established / robust fixed film technology
• Resiliance to shock and toxic loads
• Suitable for below-ground, partially buried or above-ground installation
• Compact footprint
• Low environmental impact
• Minimal operational input required
• Low whole-life costs, such as energy consumption
• Design provides accurate sizing and guaranteed effluent discharge quality
• Random packed media with a surface area in the range of 100 to 400 m2/m3 and a voidage of 95%
• High media voidage reduces or eliminates the requirement for backwashing
• Typical design detention times provide buffering ability to handle peak loadings characteristic of smaller works
• Containerised sizing for ease of transport to site

The BioSAF is available in three forms:

• Integral BioSAF Package Plant (30 - 250 PE)
• Modular BioSAF (up to 800 PE, or in multiples up to 3000 PE)
• Custom-Built BioSAF (1000 PE +)

A complete integral treatment process, supplied in GRP cylindrical tank available in a variety of sizes to treat a population equivalent (PE) of between 30 and 250.

The complete treatment process includes three stages of operation, including:

• Stage 1: Screening and grit removal; sludge storage; primary settlement;
• Stage 2: SAF stage for aerobic fixed film biological treatment;
• Stage 3: Humus settlement stage with air lift return to septic tank.

A unit supplied in a rectangular coated or stainless steel tank, designed to be used as part of a separate unit process configuration e.g. PS / SAF / HT, suitable for treating population equivalent (PE) up to 800 or in multiples up to 3000 PE.

It is compact and simple to install with minimal disruption to the existing treatment system. The unit is ideal for upgrading existing works, for treatment at smaller sites or for emergency treatment during plant failure, maintenance or upgrading.

The units are designed and built to address specific site requirements and generally suitable for applications with a 1000 population equivalent (PE) upwards.

The units are built with either GCS or concrete tanks and utilise non-clog coarse bubble diffusers or high efficiency membrane diffusers. Like the modular BioSAFTM, the custom-built units are ideal for roughing, secondary, combined secondary or tertiary applications. Robust fixed film technology together with OPEX / CAPEX ensure BioSAFTM technology is the first choice alternative to BAFF or AS systems. BioSAFTM are ideal for treating municipal wastewaters or highly-complex industrial effluents.